rod of Asclepius has "the more ancient and authentic claim to be the emblem of medicine". Most attempts to defend the caduceus's use in a medical context date from the last quarter of the 19th century through the first quarter of the 20th, and have been characterized as "based on flimsy and pseudo-historical research". In a survey of 242 logos used by organizations related to health or medicine, Friedlander found that professional associations were more likely to display the rod of Asclepius (62%), while organizations with a commercial focus were more likely to use the caduceus (76%). Hospitals were an exception (37% used a staff of Asclepius whereas 63% used a caduceus). Friedlander felt it likely that this might reflect the fact that "professional medical organizations have more often sought a real understanding of the meaning of the two symbols whereas commercial organizations have been less interested in the historical basis of their logo or insignia and more concerned with how well a certain symbol will be recognized by the iconographically unsophisticated audience they are trying to attract to their wares." The use of the caduceus in a medical context has long been frowned upon by many professionals, academics and others who are familiar with the historical significance of both symbols. This has occasioned impassioned remarks by those frustrated with the continuing confusion. It has been observed that the caduceus is particularly inappropriate for use as a medical symbol due to its long associations with the Greek god Hermes, who was patron of commerce and traders as well as thieves, liars, and gamblers. On the other hand, it has also been remarked – not without considerable irony – that commercial aims in medicine, especially in the United States of America, make the caduceus an appropriate symbol, at least for some physicians. Others are unapologetic about the association of medicine with commerce, recognizing the importance of "advertising essential for competitive marketing", and suggesting that it is up to individual physicians to choose between the two symbols, based on their own views about what associations are appropriate. The AMA has used the Rod of Asclepius for over a century, and its current logo since 2005. In North America, there are calls to clarify the symbol and to move to a uniform use of the rod of Asclepius. For example, the director of communications of the Minnesota Medical Association is quoted as saying,